I wasn't the biggest fan of Cangel, or of Cordelia's character in general for the latter part of the season. Didn't care for her transformation into a half-demon with random deus ex machina powers and none of her old wit.
Plenty of other good things about the season, though. Holtz, Darla, and especially Wesley. I thought Wes's arc was excellently written, and Alexis Denisof was brilliant. Wesley was always the one willing to make the hard choices, and his decision to take Connor really did seem like the best option to him at the time, but at the same time I couldn't fault Angel for his furious reaction to it either.
Still a step down from season two in my opinion, but great nonetheless.